A Federation solar observatory orbiting the Amargosa star, attacked by Romulans and used by Tolian Soran to destroy the star.
The Amargosa Observatory is a Federation space station that studies the Amargosa star. Dr. Tolian Soran works there, secretly preparing a weapon able to halt nuclear fusion in a star.
In Star Trek Generations, the Enterprise-D responds to a distress call after Romulans attack the observatory. Soran then fires a trilithium probe into the Amargosa star, destroying it and the station. The destruction alters the path of the energy ribbon that leads to the Nexus, part of Soran's plan to return to it.